COLONIC TRANSIT OF DIFFERENT SIZED TABLETS IN HEALTHY-SUBJECTS

The gastrointestinal transit of single unit dosage forms (tablets) of different sizes (3 mm, mm, mm and 12 mm) was investigated in eight healthy male volunteers. The volunteers followed a strictly controlled diet containing 28 g dietary fibre ( 18.5 g non-starch polysaccharide), per day, starting six days prior to the start of the study and continuing until the study was completed. On each of the three study days, following an overnight fast, each volunteer received five control tablets (6 mm diameter) labelled with indium-111, and five variable sized tablets (3 mm. 9 mm or 12 mm diameters) labelled with technetium-99m. Tablet transit was followed using the technique of dual isotope gamma scintigraphy. Gastric emptying times, small intestinal transit times, colon arrival times and total transit times were calculated. The transit of tablets through the ileo-caecal junction was unaffected by tablet size. All tablets entered into the colon as a bolus. The 3 mm and 6 mm tablets were retained in the ascending colon for the longest period of time. Tablet streaming does not appear to be controlled solely by the diameter of the tablet. Differences in tablet volume also appear to have an effect.